<?php
/**
 *--------------------------------------------------------------------
 *
 * Sub-Class - MSI Plessey
 *
 *--------------------------------------------------------------------
 * Copyright (C) Jean-Sebastien Goupil
 * http://www.barcodephp.com
 */
include_once('BCGBarcode1D.php');

class BCGmsi extends BCGBarcode1D {
	private $checksum;

	/**
	 * Constructor.
	 */
	public function __construct() {
		parent::__construct();

		$this->keys = array('0','1','2','3','4','5','6','7','8','9');
		$this->code = array(
			'01010101',	/* 0 */
			'01010110',	/* 1 */
			'01011001',	/* 2 */
			'01011010',	/* 3 */
			'01100101',	/* 4 */
			'01100110',	/* 5 */
			'01101001',	/* 6 */
			'01101010',	/* 7 */
			'10010101',	/* 8 */
			'10010110'	/* 9 */
		);

		$this->setChecksum(0);
	}

	/**
	 * Sets how many checksums we display. 0 to 2.
	 *
	 * @param int $checksum
	 */
	public function setChecksum($checksum) {
		$checksum = intval($checksum);
		if ($checksum < 0 && $checksum > 2) {
			throw new BCGArgumentException('The checksum must be between 0 and 2 included.', 'checksum');
		}

		$this->checksum = $checksum;
	}

	/**
	 * Draws the barcode.
	 *
	 * @param resource $im
	 */
	public function draw($im) {
		// Checksum
		$this->calculateChecksum();

		// Starting Code
		$this->drawChar($im, '10', true);

		// Chars
		$c = strlen($this->text);
		for ($i = 0; $i < $c; $i++) {
			$this->drawChar($im, $this->findCode($this->text[$i]), true);
		}

		$c = count($this->checksumValue);
		for ($i = 0; $i < $c; $i++) {
			$this->drawChar($im, $this->findCode($this->checksumValue[$i]), true);
		}

		// Ending Code
		$this->drawChar($im, '010', true);
		$this->drawText($im, 0, 0, $this->positionX, $this->thickness);
	}

	/**
	 * Returns the maximal size of a barcode.
	 *
	 * @param int $w
	 * @param int $h
	 * @return int[]
	 */
	public function getDimension($w, $h) {
		$textlength = 12 * strlen($this->text);
		$startlength = 3;
		$checksumlength = $this->checksum * 12;
		$endlength = 4;

		$w += $startlength + $textlength + $checksumlength + $endlength;
		$h += $this->thickness;
		return parent::getDimension($w, $h);
	}

	/**
	 * Validates the input.
	 */
	protected function validate() {
		$c = strlen($this->text);
		if ($c === 0) {
			throw new BCGParseException('msi', 'No data has been entered.');
		}

		// Checking if all chars are allowed
		for ($i = 0; $i < $c; $i++) {
			if (array_search($this->text[$i], $this->keys) === false) {
				throw new BCGParseException('msi', 'The character \'' . $this->text[$i] . '\' is not allowed.');
			}
		}
	}

	/**
	 * Overloaded method to calculate checksum.
	 */
	protected function calculateChecksum() {
		// Forming a new number
		// If the original number is even, we take all even position
		// If the original number is odd, we take all odd position
		// 123456 = 246
		// 12345 = 135
		// Multiply by 2
		// Add up all the digit in the result (270 : 2+7+0)
		// Add up other digit not used.
		// 10 - (? Modulo 10). If result = 10, change to 0
		$last_text = $this->text;
		$this->checksumValue = array();
		for ($i = 0; $i < $this->checksum; $i++) {
			$new_text = '';
			$new_number = 0;
			$c = strlen($last_text);
			if ($c % 2 === 0) { // Even
				$starting = 1;
			} else {
				$starting = 0;
			}

			for ($j = $starting; $j < $c; $j += 2) {
				$new_text .= $last_text[$j];
			}

			$new_text = strval(intval($new_text) * 2);
			$c2 = strlen($new_text);
			for ($j = 0; $j < $c2; $j++) {
				$new_number += intval($new_text[$j]);
			}

			for ($j = ($starting === 0) ? 1 : 0; $j < $c; $j += 2) {
				$new_number += intval($last_text[$j]);
			}

			$new_number = (10 - $new_number % 10) % 10;
			$this->checksumValue[] = $new_number;
			$last_text .= $new_number;
		}
	}

	/**
	 * Overloaded method to display the checksum.
	 */
	protected function processChecksum() {
		if ($this->checksumValue === false) { // Calculate the checksum only once
			$this->calculateChecksum();
		}

		if ($this->checksumValue !== false) {
			$ret = '';
			$c = count($this->checksumValue);
			for ($i = 0; $i < $c; $i++) {
				$ret .= $this->keys[$this->checksumValue[$i]];
			}

			return $ret;
		}

		return false;
	}
}
?>